Interpretive Summary: In this study we evaluated an improved attractant for male Mediterranean fruit fly in coffee field in Hawaii. We tested the new lure against the current standard male lure and evaluated the relative attraction of different formulations and calculated the residual activity of the lures after 6 weeks. We found that the racemic lure ( minus ceralure B1) was significantly better than the current standard (trimedlure) in nearly all of the trials. And that it is inherently a more addtractive chemical to the flies that the standard trimedlure. If the racemic lure can be manufactured cost-effectively, it could replace trimedlure in detection and control programs against this pest.

Technical Abstract:
Equal moles of racemic ceralure B1 and trimedlure isomer C were compared on cotton wicks in field tests for attractancy and residual compound after 2,4, and 7 days analyzed for longevity and persistence in the field. Ceralure B1 was equally attractive as trimedlure C for the first two days and significantly more attractive at 4 and 7 days based on trap counts of captured male Mediterranean fruit flies. Residue analysis of weathered wicks showed that the trimedlure C lasted for just two days in our field evaluations with no compound detected at 4 and 7 days. Ceralure B1 showed a similar (but less steep) release of compound from cotton wicks with measurable material present after 7 days. Thus, based on the amounts of chemicals released, ceralure B1 was more active even in the first two days.
Ceralure B1 was also formulated in a plastic matrix, (ceralure coin) at three different dosages and tested for attractancy in the field against a 2g Trimedlure plug. A 150 mg ceralure B1 coin was equally attractive as a commercial 2g trimedlure plug while a 300 mg coin was significantly more attractive during a 6-8 week deployment. While our results clearly show that ceralure B1 is a superior attractant than trimedlure, costs of synthesis need to be considered as part of an overall program management strategy.